Diaphragm for the objectives of stereocameras



J. MITTASCH DIAPHRAGM FOR Tm: OBJECTIVES OF STEREOGAMERAS vii-a Oct, 15. 1923 diaphragms.

Patented Oct. 21', 1924.

UNITED STATES PATENT. orrlca.

JOHANNES I ITTASCH, OF HEIDELBEBG, GERMANY.

DIAPHRAGI I03 THE OBJECTIVES OFv STEBEOCAIE RAS.

Application fled October 15, 1923. Serial No. 668,609.

Toallwhomitmay concern:

Be it known that I, J OHANNES Mrrrason, a citizen of the German Republic, residing at Heidelberg, German have invented certain new and usefu Improvements in Diaphragms for the Objectives of Stereocameras, for which application for patent has been filed in Germany on the 8th of December, 1922, and ofwhich the following is a specification.

It has become known to regulate the light intensity of the objective in photographic apparatus, with the aid of slidingrevolvingor iris diaphragms and to bring these diaphragms into efiect in the most various manners. The invention relates to the well known rotary diaphragms with exposure apertures of different size in their application to stereocameras.

The arrangement is such that photographscan be taken with both objectives simultaneous% or only with one of the two objectives. ith this object in view two rotary diaphragms are arranged according to this invention which gear with one another and have each two sets of apertures of different dimensions. On the one diaphragmthese two sets of apertures are arranged in direct succession, the distance between the several apertures being equal. On the other diaphragm a part of therotary diaphragm follows upon the one set of apertures which acts like a covering diaphragm, the secondset of apertures following only on this part of the rotary diaphragm. The displacement of the two sets of apertures on the second diaphragm for an angle which depends on the number of apertures has for its object to enable the alternating use of the ob'ectives also for single-exposures.

e invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming a art of this s ification, with the understan ing that whfi on the drawing one embodiment of the invention'is disclosed, the invention is not confined to any strict conformity with the showing of the drawing, but may be embodied in any manner which does not make a material departure from the salient features of the invention.

In the drawing:

Fig. 1 is a perspective view of a stereocamera with t e improved arrangement of Fig. 2 shows the diaphragms on a larger scale than that used in Fig. 1, the front wall of the'camera being removed.

In the front wall a of a stereocamera having the objective apertures b and a respect-ively the two rotary diaphragms d and e are mounted which gear the one with the other. Each diaphragm has two sets A and B of apertures with the values of for instance F==18, 12, 9, 18 and 12 which are designated on the left diaphragm with the reference characters f, g, h, i andk and on the right diaphragm with f, g, h, i and is. One of the two diaphragms has further a number of small holes m uniformly distributed over the circumference and serving as notches for a stud n of an elastic blade 0. The sets A and B of apertures are arranged on the one diaphragm in direct succession so that the distance is equal between the several appertures. On the other diaphragm the apertures f, g, h of the first set A stand at equal distances a art, but between aperture 72. of set A an aperture i of set B is a distance three times that between every two apertures of the first or second set. The solid part of the rotary diaphragm d situated between the apertures f and k on the one hand and the parts of the rotary diaphragm e situated between the apertures 71. and i and f k on the other hand act as covering diaphragms when single exposures have to be made or when the two objectives have to be obturated.

Around the axes of rotation. of the diaphragms index figures and characters are arranged, 9, 12, 18, 12, 18, R, R and C on the rotary diaphragm d and 9, 12, 18, L,.L, 12, 18 and C on t e rotary diaphragm e, of which always two signs belonging together appear in the two windows 1 and 8. Owing to the arrangements of the diaphragm apertures and of the" indexing signs the followin positions of the diaphragms are possi la and can be read .at once.

At the position shown in Fig. 2 the lar est diaphragm apertures (F=9) f and f stand behind the objective apertures b and 0 By rotating in the direction of arrow rotated the apertures 11 or is will come on' the other side into the optical axis, while the objective aperture for diaphragm e is covered by said diaphragm. In the window 1' the figures 12 or 18 are visible and in the window 8 the character L (left) is visible both times. These positions serve for single view taking on. the left half of the plate. If the diaphragm e is still rotated furtherthe objective 7 remains covered, the apertures 01 or In standing in front ofthe objective f. In the window 1' appears in this case the character R (right) and in the window 8 appears the figure 12 or 18. These positions serve for single view taking on the right half of the 'late. If the rotary diaphragm is still furt er rotated both objectives are covered and the two characters C (closed) appearin the Windows 1', s.

I claim 1. Diaphragms for the objectives of regard to one another, indexing signs on said diaphragms, and the front wall of the camera having two windows one for one of the indexing signs of each diaphragm.

In testimony whereof I aflix my signature in presence of two witnesses.

JOHANNES MITTASCH. Witnesses:

G. C. L. B. Mme, H. Scmcmm'r. 

